The fight over a public insurance option has grabbed all the attention, but President Obama’s health care plan faces plenty of other obstacles, from the price tag to ideological battles over immigration and abortion to questions over who would be kicked off their current plans.

Any of these could be fatal to Mr. Obama’s goal, and coupled with the looming deadline of the end of this year’s legislative session, they show just how much Mr. Obama will have to overcome if he hopes to sign a bill this year.

“It’s not just the government-run program that’s bad about this bill. That’s a relatively small portion of the bill, and there are another 1,100 pages that have many egregious aspects as well,” said Rep. Tom Price of Georgia, who as chairman of the Republican Study Committee leads the conservative caucus in the House.

Mr. Price, an orthopedic physician, cited the potential for rationed care and mandates that would punish individuals who don’t purchase insurance or businesses that don’t offer it as sticking points that potentially could derail Democrats’ efforts.

At the other end of the spectrum, liberal Democrats have drawn a line in the sand on requiring a government-sponsored health care plan, or public option, to compete with private insurers. But they’ll also need to see a “robust” government subsidy to help some Americans pay for insurance, said Rep. Lynn Woolsey, California Democrat.

According to excerpts released by the White House ahead of his address to Congress Wednesday night, Mr. Obama said that despite the discord, “There is agreement in this chamber on about 80 percent of what needs to be done, putting us closer to the goal of reform than we have ever been.”

The president’s task now is to corral enough of a coalition on the other 20 percent that he can pass a bill that still meets his goals of lowering health care costs and expanding coverage.

To do that, he’ll have to engage with the fiscally conservative Blue Dog House Democrats, who say they’ll vote only for a plan that doesn’t add to the deficit - something that the official scorekeeper, the Congressional Budget Office, says would happen under at least some of the bills winding their way through the legislative process.

Some Blue Dogs also have said they need more assurances the bill won’t end up expanding taxpayer funding for abortions or lead to illegal immigrants gaining health insurance benefits.

Mr. Obama spent plenty of time Wednesday night trying to answer those objections, saying the plan he favors would be silent on covering abortions and that he does not intend to expand coverage to illegal immigrants in this measure.

He also repeated his own vow that any bill not increase the deficit.

Those pushing for a bill this year cautioned against assuming the obstacles are insurmountable.

Ralph G. Neas, chief executive officer of the National Coalition on Health Care, said the untold story of the debate is how much agreement there is on big issues. He said all sides agree that insurance companies should be required to provide coverage regardless of pre-existing conditions, should eliminate caps on the amount of lifetime benefits and must allow portability of insurance even when workers change jobs.

Mr. Neas said those changes would help those who already have insurance, and said Mr. Obama’s challenge during the rest of the debate will be to “turn this into a kitchen-table issue so that every single family knows what’s at stake.”

“The president can convince people that it will ensure stability and relieve them of some of this economic anxiety that plagues all of us,” he said.

He said he’s encouraged that major business groups have been at the table for months, and have not jumped out of discussions even as the debate heated up this summer.

Republicans said there’s also agreement on all sides for some type of malpractice reform, which has helped drive up the cost of insurance, and on allowing small businesses to pool together to get better rates.

But unlike Mr. Neas, Republicans said a bill shouldn’t go beyond those areas where there’s a strong bipartisan majority.

“I would hope the president would soon realize that that’s what the American people want,” said House Minority Leader John A. Boehner, Ohio Republican. “They want the current system to work better. They don’t want it replaced with a big, government-run plan.”